1. Field of the Invention
This invention relates to a hinge assembly of a turbine engine nozzle assembly and, more particularly, to a bell crank mechanism of a turbine engine nozzle assembly employing a novel self-lubricated bearing assembly.
2. Description of the Related Art
As is generally known in the art, turbine engine nozzle assemblies typically include a rod or bolt attached to a flap by means of, for example, at least one hinge assembly such as, for example, a bell crank linkage assembly. The bell crank assembly translates horizontal movement into vertical movement or, vise versa, for actuating the flap. Conventional bell crank assemblies include ball bearings between a housing of the bell crank assembly and the bolt to reduce friction, minimize wear and improve performance. High temperature and high frequency vibration within the operating environment of the turbine engine nozzles has a significant impact on the performance and life cycle of components of conventional bell crank assemblies. For example, the ball bearings generally can not be sufficiently lubricated within the operating environment of the turbine engine nozzle. Therefore, the ball bearings require frequent maintenance and replacement resulting in high operating costs.
FIG. 1 illustrates a portion of a conventional turbine engine nozzle assembly including a bell crank linkage assembly, shown generally at 10, affixed about a threaded stud or bolt 20. As is generally known in the art, the bolt 20 is attached to a flap (not shown). As shown in FIG. 1, the bell crank assembly 10 is retained about the bolt 20 by a locking tab washer 30 and a nut 40. Two ball bearings 50 and 60 are installed within the bell crank assembly 10 such that outer races 52 and 62 of the ball bearings 50 and 60, respectively, contact an inner diameter 12 of the bell crank assembly 10 and inner races 54 and 64 of the ball bearings 50 and 60 contact an outer diameter 22 of the bolt 20. The ball bearings 50 and 60 are intended to reduce friction and minimize wear between the bell crank assembly 10 and the bolt 20. As noted above in the Background portion of this disclosure, the operating environment of the turbine engine nozzle assembly includes high temperatures and high frequency vibration. Additionally, in conventional designs, it is difficult to lubricate the ball bearings 50 and 60 once installed within the bell crank assembly 10. As a result, the ball bearings 50 and 60 require frequent maintenance and replacement leading to increased operational costs.
Accordingly, the inventors have realized that a need exists for an improved bell crank assembly having components that operate more efficiently within high temperature, high vibration environment of a turbine engine nozzle.